The invention is related to micro-electro-mechanical systems (MEMS), and specifically to neural probes and methods of making thereof.
There is an increasing demand in neuroscience for large scale recording of neuronal activity (see Buzsáki, G., “Large-scale recording of neuronal ensembles,” Nature Neuroscience, 2004, pp. 446-451, vol. 7). Techniques such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) provide coarse grained views on synchronized activity, but they do not afford much insight into the brain's circuitry at the level of single neurons. The introduction of multielectrode silicon probes (see Blanche et al., “Polytrodes: High-density silicon electrode arrays for large-scale multiunit recording,” Journal of Neurophysiology, 2005, pp. 2987-3000, vol. 93, no. 5; Campbell et al, “A silicon-based, three-dimensional neural interface: manufacturing processes for an intracortical electrode array,” IEEE Trans. Biomed. Eng., 1991. pp. 758-768; Drake et al., “Performance of planar multisite microprobes in recording extracellular single-unit intracortical activity,” IEEE Trans. Biomed. Eng., 1988, pp. 719-732, vol. 35, no. 9; Najafi et al., “A high-yield IC-compatible multichannel recording array,” IEEE Trans Electron Devices, 1985, pp. 1206-1211, vol. 32, no. 7; Norlin et al., “A 32-site neural recording probe fabricated by DRIE of SOI substrates,” Journal of Micromechanics and Microengineering, 2002, pp. 414-419, vol. 12, no. 4; Wise et al., “Integrated sensors, MEMS, and microsystems: Reflections on a fantastic voyage,” Sensors and Actuators a-Physical, 2007, pp. 39-50, vol. 136, no. 1) has led to great advances in large scale recording with high (i.e. single-cell) resolution. However, current tools often fall short of providing a densely populated 3-dimensional ‘activity map,’ which may offer a better understanding of the circuitry of cell assemblies in the brain.
A need exists in the scientific and medical community to develop high recording density devices that can measure electrical multineuronal activity in the brain with single cell and spike time precision.